Only 38% of voters think Biden will be alive at the end of a second term and more than a third believe Kamala Harris will be president by January 2029 if 81-year-old is reelected

Only 38 percent of likely 2024 voters believe President Joe Biden will be alive at the end of another four-year term, according to an exclusive poll for DailyMail.com.

And that means one thing: Vice President Kamala Harris is just as likely to be in the top job as Biden come January 2029 if he wins reelection.

Some 36 percent of likely voters believe Harris will be president at the end of the term. The exact same proportion as think Biden will be in the job.

The results show how the 81-year-old president's age will be a major factor on November 5 when voters pick the commander in chief they want for the next four years.

Donald Trump, his Republican rival, is only four years younger but voters harbor fewer doubts.

More than half say they are confident he will make it through a full term, with 34 percent saying they have doubts.

Either way, the results show how Republicans and Democrats will have to weigh up not just their choice of president but also consider who is likely to step into the breach if ill health—or worse—incapacitates the leader of the free world.

'Voters think Biden is too old, and they are not changing their mind,' said James Johnson, cofounder of J.L. Partners, which conducted the poll.

'The difficulty for Biden is that views of him are not shaped through events such as his State of the Union address—which people who had seen it felt was fiery—but through consumption of the hundreds of viral social media clips of Biden stumbling and slurring. 

'That solid perception that he is too old feeds through to a sense he is too weak, and it is a major problem for him going into November. Frankly, they do not think he is up to the job—and that makes his re-election a much harder task.'

Biden would be 86 at the end of a second term. 

And he tackled the age question directly in his State of The Union address.

'My fellow Americans,' said Biden as he wound up to his conclusion, 'the issue facing our nation isn't how old we are it’s how old our ideas are?

'Hate, anger, revenge, retribution are among the oldest of ideas.'

Yet the most viral moment may have been an example of frailty, when he mispronounced the name of 'Laken Riley,' a women murdered by an illegal immigrant as 'Lincoln Riley.'   

He also frequently uses humor to try to defuse the issue.

'I know it may not look like it, but I've been around a while,' he said during the State of the Union.

But he was buffeted by a slew of negative headlines after a damning special counsel report that claimed, during hours of questioning, that he forgot the date on which his beloved son Beau died and that the president would come across as 'an elderly man with a poor memory' to a jury.

(When the transcript of the interviews was released, however, Biden's performance was far better than the condensed report suggested.) 

Trump has attacked Biden repeatedly as unfit for office because of his age. But he too has suffered from unforced errors and verbal gaffes at public events that some Republican say show his declining performance.

'Putin has so little respect for Obama that he's starting to throw around the nuclear word,' said Trump said at a rally in Richmond, Virginia, earlier this month, muddling the current president with a Democratic predecessor.

For now, Trump has the upper hand. A separate DailyMail.com/J.L. Partners poll of 1000 likely voters found that the former president has maintained the four-point lead he has held since December.

The Biden campaign did not respond to a request for comment.